A341e Pulse Per Mile - Need this ASAP

[nismo4life]

Really hoping someone here can tell me definitively what the PPM for the stock LS400 is. This is the final thing I need to make everything functional for my swap, and I'd really like to know how fast I'm going into a corner before I pull on the fun lever (hydrobrake). Thanks guys!

 

[George_R]

What chassis is your transmission from?

 

[nismo4life]

What chassis is your transmission from?

Its a 1992 LS400. The vin reads UF11, and I believe it is a late 1992 build, something around October or November I can't remember, but I can confirm in about 20 minutes.

 

[George_R]

Early 92 ls400 should have 4-pole reluctor for sp2+/sp2- sensor (4 pulses per tailshaft revolution).

Don't remember about later models, but in general if there's a single sensor in the tail part I'd expect 12 pulses per rev. You can unscrew the sensor, turn the tailshaft and count the teeths manually. Then take into account diff ratio and the distance wheel travels per single revolution

 

[nismo4life]

Early 92 ls400 should have 4-pole reluctor for sp2+/sp2- sensor (4 pulses per tailshaft revolution).

Don't remember about later models, but in general if there's a single sensor in the tail part I'd expect 12 pulses per rev. You can unscrew the sensor, turn the tailshaft and count the teeths manually. Then take into account diff ratio and the distance wheel travels per single revolution

I lied, its a 1/92 build. And you lost me on the math lol.

 

[George_R]

225/60/R16 sized wheel travels 2.125 meters per single revolution. Or you can say it makes 0.47 of its complete turn per every meter. With diff. ratio of 3.27 tailshaft makes 1.54 turns per meter. Each turn produces 4 pulses of the reluctor type speed sensor (one that connects to SP2+/SP2- terminals of the ECU, but there's one more sensor in the tail piece of transmission). So we have 1.54*4=6.15 pulses per meter, or ~10.000 pulses per mile

So...as long as you know pulses per rev, you can translate them into pulses per mile as I shown you. To check 2-wire sensor's pulses per rev, you unscrew the sensor, rotate tailshaft and count the teeths you see through the hole. To check 3-wire sensor's pulses per rev, you will need a couple wires and small bulb (best if you find LED bulb)

 

[nismo4life]

225/60/R16 sized wheel travels 2.125 meters per single revolution. Or you can say it makes 0.47 of its complete turn per every meter. With diff. ratio of 3.27 tailshaft makes 1.54 turns per meter. Each turn produces 4 pulses of the reluctor type speed sensor (one that connects to SP2+/SP2- terminals of the ECU, but there's one more sensor in the tail piece of transmission). So we have 1.54*4=6.15 pulses per meter, or ~10.000 pulses per mile

So...as long as you know pulses per rev, you can translate them into pulses per mile as I shown you. To check 2-wire sensor's pulses per rev, you unscrew the sensor, rotate tailshaft and count the teeths you see through the hole. To check 3-wire sensor's pulses per rev, you will need a couple wires and small bulb (best if you find LED bulb)

Oh wow...interesting. Makes sense though. I have an SGI-5 from Dakota Digital on the way, as well as the 240sx VSS PPM, though 2000 ppm sounds like quite a lot to me?

 

[George_R]

2000 ppm sounds like 5 times less than you need, but most aftermarket gauges are tunable.

Again, the 3-wire sensor (one that connects to cluster in LS400) may have different ppm. I got a number of FSM scans and there's some contradiction between them regarding the 3-wire sensor. I never went into much detail as I only once used that old engine in a conversion (newer 1UZ's run only one 2-wire sensor with 12 pulses per rev)